There's an OEM coil on ebay for your car here:
http://cgi.ebay.com/ebaymotors/BOSCH-COIL-Mercedes-Benz-190-200-220-230-250-280-300_W0QQitemZ130065603760QQihZ003QQcategoryZ10076QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
No idea about the seller though, he's in Cypress?!?? It's kind of a gamble, but I bought one from him, I'll let you know how it goes.
Nothing like original parts to make it run right...